Hand held appliance

ABSTRACT

A hair care appliance comprising a body having an outer wall, a duct extending within the outer wall, a primary fluid flow path extending between the duct and the outer wall, a flow directing plate within the primary fluid flow path and at least two guide surfaces located on the flow directing plate wherein the at least two guide surfaces meet at an apex. The body may have a first end, a second end and a longitudinal axis extending from the first end to the second end, wherein the fluid flow path extends along the longitudinal axis. The flow directing plate may be generally orthogonal to the longitudinal axis. The at least two guide surfaces may extend along the longitudinal axis towards the apex. Within the body the primary fluid flow path may be generally annular.

REFERENCE TO RELATED APPLICATIONS

This application claims the priority of United Kingdom Application No. 1520871.3, filed Nov. 26, 2015, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a hand held appliance, in particular a hair care appliance and a fluid outlet from such an appliance.

BACKGROUND OF THE INVENTION

Blowers and in particular hot air blowers are used for a variety of applications such as drying substances such as paint or hair and cleaning or stripping surface layers. In addition, hot air blowers such as hot styling brushes are used to style hair from a wet or dry condition.

Generally, a motor and fan are provided which draw fluid into a body; the fluid may be heated prior to exiting the body. The motor is susceptible to damage from foreign objects such as dirt or hair so conventionally a filter is provided at the fluid intake end of the blower. Conventionally such appliances are provided with a nozzle which can be attached and detached from the appliance and changes the shape and velocity of fluid flow that exits the appliance. Such nozzles can be used to focus the outflow of the appliance or to diffuse the outflow depending on the requirements of the user at that time.

SUMMARY OF THE INVENTION

According to a first aspect, the invention provides a hair care appliance comprising a body having an outer wall, an inner wall extending within the outer wall, a primary fluid flow path extending between the inner wall and the outer wall, a flow directing plate within the primary fluid flow path and at least two guide surfaces located on the flow directing plate wherein the at least two guide surfaces meet at an apex.

Preferably, the body has a first end, a second end and a longitudinal axis A-A extending from the first end to the second end, wherein the fluid flow path extends along the longitudinal axis A-A.

It is preferred that the flow directing plate is generally orthogonal to the longitudinal axis A-A.

Preferably, the at least two guide surfaces extend along the longitudinal axis A-A towards the apex.

It is preferred that within the body the primary fluid flow path is generally annular.

Preferably, the appliance further comprises a handle, wherein the primary fluid flow path comprises a primary fluid inlet into the appliance, and wherein the primary fluid inlet is in the handle.

It is preferred that within the handle the primary fluid flow path is generally circular.

Preferably, the flow directing plate is for directing flow from the handle as it enters into the body.

It is preferred that the flow directing plate deflects the primary fluid flow around the duct.

Preferably, within the primary fluid flow path, primary fluid flows through the handle in a first direction and in the body in a second direction.

It is preferred that the at least two guide surfaces are radially spaced from the handle.

Preferably, the body further comprises a heater, wherein the heater is located downstream of the flow directing plate.

Preferably, the body is generally tubular and has an upper half and a lower half and the handle is connected to the lower half. It is preferred that the region of relatively high velocity is in the lower half of the body. Preferably, the region of relatively low velocity is in the upper half of the body.

Preferably, the primary fluid flow path has a region of relatively high velocity and a region of relatively low velocity and the at least two guide surfaces are in the region of relatively low velocity.

It is preferred that larger components of the PCB are located in the upper half of the body. Preferably, smaller components of the PCB are located in the lower half of the body. It is preferred that larger components of the PCB are components which extend the furthest from a circuit board on which they are mounted.

Preferably, the appliance is a hairdryer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by example, with reference to the accompanying drawings, of which:

FIG. 1 shows a side view of an appliance according to the invention;

FIG. 2 shows a cross section through the appliance of FIG. 1;

FIG. 3 shows an enlarged cross section through an appliance according to the invention;

FIG. 4 shows a front isometric view of a flow directing plate according to the invention; and

FIG. 5 shows a further isometric view of a flow directing plate according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 show a hairdryer 10 with a handle 20 and a body 30. The handle has a first end 22 which is connected to the body 30 and a second end 24 distal from the body 30 and which includes a primary fluid inlet 40. Power is supplied to the hairdryer 10 via a cable 50. At a distal end of the cable 50 from the hairdryer 10 a plug (not shown) is provided, the plug may provide electrical connection to mains power or to a battery pack for example.

The handle 20 has an outer wall 200 which extends from the body 30 towards a distal end 24 of the handle. At the distal end 24 of the handle an end wall 210 extends across the outer wall 200. The cable 50 enters the hairdryer through this end wall 210. The primary fluid inlet 40 in the handle 20 includes first apertures that extend around and along 42 the outer wall 200 of the handle in a series of rows and/or columns that extend from the distal end 24 of the handle 20 and second apertures that extend across 46 and through the end wall 210 of the handle 20. The cable 50 is located approximately in the middle of the end wall 210 so extends from the centre of the handle 20. The handle 20 has a longitudinal axis X-X along which the outer wall 200 extends from the body 30 towards the distal end 24.

It is preferred that the cable 50 extends centrally from the handle 20 as this means the hairdryer is balanced regardless of the orientation of the handle 20 in a users' hand. Also, if the user moves the position of their hand on the handle 20 there will be no tugging from the cable 50 as it does not change position with respect to the hand when the hand is moved. If the cable were offset and nearer one side of the handle then the weight distribution of the hairdryer would change with orientation which is distracting for the user.

Upstream of the primary fluid inlet 40, a fan unit 70 is provided. The fan unit 70 includes a fan and a motor. The fan unit 70 draws fluid through the primary fluid inlet 40 towards the body 30 through a primary fluid flow path 400 that extends from the primary fluid inlet 40 and into the body 30 where the handle 20 and the body 30 are joined 90. The body 30 has a first end 32 and a second end 34, the primary fluid flow path 400 continues through the body 30 towards the second end 34 of the body, around a heater 80 and to a primary fluid outlet 440 where fluid that is drawn in by the fan unit exits the primary fluid flow path 400. The primary fluid flow path 400 is non-linear and flows through the handle 20 in a first direction and through the body 30 in a second direction which is orthogonal to the first direction.

The body 30 includes an outer wall 360 and an inner duct 310. The primary fluid flow path 400 extends along the body from the junction 90 of the handle 20 and the body 30 between the outer wall 360 and the inner duct 310 towards the primary fluid outlet 440 at the second end 34 of the body 30.

An inner wall 260 extends within the outer wall 360. The inner wall 260 at least partially defines the primary fluid outlet 440 and extends from the second end 34 of the body 30 between the inner duct 310 and the outer wall 360.

Another fluid flow path is provided within the body; this flow is not directly processed by the fan unit or the heater but is drawn into the hairdryer by the action of the fan unit producing the primary flow through the hairdryer. This fluid flow is entrained into the hairdryer by the fluid flowing through the primary fluid flow path 400.

The first end 32 of the body includes a fluid inlet 320 and the second end 34 of the body includes a fluid outlet 340. Both the fluid inlet 320 and the fluid outlet 340 are at least partially defined by the inner duct 310 which is an inner wall of the body 30 and extends within and along the body. A fluid flow path 300 extends within the inner duct 310 from the fluid inlet 320 to the fluid outlet 340. At the first end 32 of the body 30, a side wall 350 extends between the outer wall 360 and the inner duct 310. This side wall 350 at least partially defines the fluid inlet 320. The primary fluid outlet 440 is annular and surrounds the fluid flow path.

A PCB (printed circuit board) 75 including the control electronics for the hairdryer is located in the body 30 near the side wall 350 and fluid inlet 320. The PCB 75 is ring shaped and extends round the inner duct 310 between the inner duct 310 and the outer wall 360. The PCB 75 is in fluid communication with the primary fluid flow path 400. The PCB 75 extends about the fluid flow path 300 and is isolated from the fluid flow path 300 by the inner duct 310.

The PCB 75 controls parameters such as the temperature of the heater 80 and the speed of rotation of the fan unit 70. Internal wiring (not shown) electrically connects the PCB 75 to the heater 80 and the fan unit 70 and the cable 50. Control buttons 62, 64 are provided and connected to the PCB 75 to enable a user to select from a range of temperature settings and flow rates for example.

Downstream of the PCB 75, is the heater 80 and a flow directing plate 700 is provided between the PCB 75 and the heater 80. The flow directing plate provides thermal protection for the PCB 75 when the heater 80 switched on amongst other things.

In use, fluid is drawn into the primary fluid flow path 400 by the action of the fan unit 70, is optionally heated by the heater 80 and exits from the primary fluid outlet 440. This processed flow causes fluid to be entrained into the fluid flow path 300 at the fluid inlet 320. The fluid combines with the processed flow at the second end 34 of the body. In the example shown in FIG. 2, the processed flow exits the primary fluid outlet 440 and the hairdryer as an annular flow which surrounds the entrained flow that exits from the hairdryer via the fluid outlet 340. Thus fluid that is processed by the fan unit and heater is augmented by the entrained flow.

Referring now to FIGS. 3, 4 and 5 in particular, the flow directing plate 700 will now be described. The handle 20 is generally tubular and the primary fluid flow path 400 is generally circular as it enters the junction 90 between the handle 20 and the body 30. At this point the primary fluid flow path 400 changes direction by 90° and from a circular flow to an annular flow around the duct 310 between the duct 310 and the outer wall 360 of the body 30. These changes affect the velocity of flow in the primary fluid flow path 400.

If we consider that the body 30 is generally symmetrical about a longitudinal axis A-A which extends along the length of the body 30, the duct 310 and outer wall 360 are concentric as is the heater 80 located between the duct 310 and the outer wall 360.

When the primary fluid in the primary fluid flow path 400 reaches the junction 90 between the body 30 and the handle 20, the primary fluid must change both direction and shape. This creates a region of high velocity flow in the body 30 by the junction 90 and a region of lower velocity flow radially spaced within the body 30 from the junction 90. If we consider the body 30 to have an upper half 380 and a lower half 390 where the upper half 380 is radially spaced away from the handle 20 and the lower half 390 includes the junction 90 between the body 30 and the handle 20 then the lower half 390 has flow at a relatively higher velocity than the upper half 380.

The flow directing plate 700 is provided to curve or direct the flow within the primary fluid flow path 400 over and around the PCB 75 and components mounted on the PCB to minimise any pressure losses due to the location of the PCB and due to the change of direction of the primary fluid flow path 400 as it enters the body 30.

The fluid entering the body 30 flows both towards the primary fluid outlet 440 and around the duct 310 to the upper part 380 of the body 30. The flow directing plate 700 includes a pair of guide surfaces 710, 720 which direct fluid in the upper part 380 of the body 30 as the fluid flows around the duct 310 on either side of the duct 310 to meet in the upper part 380 of the body 30. The two guide surfaces 710, 720 are preferably integral with the flow directing plate 700 and are arranged to that each guide surface 710, 720 curves away from the flow directing plate 700 towards the second end 34 of the body 30 and meets the other respective guide surface 720, 710 at an apex 730.

The two guide surfaces 710, 720 reduce turbulence within the body 30 by directing the fluid flowing within the upper half 380 of the body 30 towards the primary fluid outlet 440.

The invention has been described in detail with respect to a hairdryer however, it is applicable to any appliance that draws in a fluid and directs the outflow of that fluid from the appliance.

The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect.

The fluid that flows through the appliance is generally air, but may be a different combination of gases or gas and can include additives to improve performance of the appliance or the impact the appliance has on an object the output is directed at for example, hair and the styling of that hair.

The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art. 

1. A hair care appliance comprising a body having an outer wall a first end, a second end and a longitudinal axis extending from the first end to the second end, a duct extending within the outer wall, a primary fluid flow path extending between the duct and the outer wall along the longitudinal axis towards the second end to a primary fluid outlet, a flow directing plate within the primary fluid flow path and at least two guide surfaces located on the flow directing plate wherein the at least two guide surfaces meet at an apex and wherein the at least two guide surfaces extend along the longitudinal axis towards the apex.
 2. The appliance of claim 1, wherein the fluid flow path extends along the longitudinal axis.
 3. The appliance of claim 2, wherein the flow directing plate is orthogonal to the longitudinal axis.
 4. The appliance of claim 1, wherein within the body, the primary fluid flow path is annular.
 5. The appliance of claim 4, further comprising a handle, wherein the primary fluid flow path comprises a primary fluid inlet into the appliance, and the primary fluid inlet is in the handle.
 6. The appliance of claim 5, wherein within the handle, the primary fluid flow path is circular.
 7. The appliance of claim 6, wherein the flow directing plate is for directing flow from the handle as it enters into the body.
 8. The appliance of claim 6, wherein the flow directing plate deflects the primary fluid flow around the duct.
 9. The appliance of claim 5, wherein within the primary fluid flow path, primary fluid flows through the handle in a first direction and in the body in a second direction.
 10. The appliance of claim 9, wherein the at least two guide surfaces direct primary fluid flow from the first direction to the second direction.
 11. The appliance of claim 5, wherein the at least two guide surfaces are radially spaced from the handle.
 12. The appliance of claim 11, wherein the body further comprises a heater and the heater is located downstream of the flow directing plate.
 13. The appliance of claim 1, wherein the appliance is a hairdryer. 